19-1296; Rev 2; 1/01
MAX2510 Evaluation Kit
General Description
The MAX2510 evaluation kit (EV kit) simplifies testing of
the MAX2510 low-power IF transceiver with limiter/
received-signal-strength indicator (RSSI) and quadra-
ture modulator. This EV kit allows simple evaluation of
all chip functions in a 50Ω test environment.
Features
o
+2.7V to +5.5V Single-Supply Operation
o
Allows Testing of Advanced Power Management
(four modes):
< 1nA Shutdown
Receive
Transport
Standby
o
50Ω SMA Connector Interface
o
Fully Assembled and Tested
Evaluates: MAX2510
Component Suppliers
SUPPLIER
Coilcraft
Murata-Erie
Sprague
PHONE/
FAX
(847) 639-6400/
(847) 639-1469
(814) 237-1431/
(814) 238-0490
(603) 224-1961/
(603) 224-1430
INTERNET
http://www.coilcraft.com
http://www.murata.com
—
Ordering Information
PART
MAX2510EVKIT-SO
TEMP. RANGE
-40°C to +85°C
IC PACKAGE
28 QSOP
Component List
DESIGNATION QTY
C1, C3
C2
C4
C6, C8
C5, C10,
C30, C31
C7, C9, C12,
C13, C21, C22,
C23, C27
C14, C15,
C17, C19
C18, C25
C20, C29
C24
L2
L3, L4
LO IN, I, Q,
RXIN,
RXIN,
TXOUT,
TXOUT,
MIXOUT, LIMIN
2
1
1
2
0
DESCRIPTION
0.01µF capacitors
330pF ceramic capacitor
0.047µF capacitor
47pF capacitors (0603)
Not installed
DESIGNATION QTY
R3, R11, R17
R4, R7, R8, R14
R1, R5
R9
R10, R15
8
4
2
2
1
1
2
0.1µF capacitors
0.001µF capacitors
10pF capacitors (0603)
0.022µF capacitors
10µF tantalum capacitor
Sprague 293D106X0010C2
82nH inductor
Coilcraft 0805HS-820TKBC
47nH inductors
Coilcraft 0805HS-470TKBC
50Ω edge-mount SMA connectors
E.F. Johnson 142-0701-801
Note:
All resistors, capacitors, and inductors are surface-
mount components with an 0805 footprint, unless otherwise
specified. Filter U2 and the various jumpers are through-hole
mounted.
1
RXEN, TXEN
None
None
2
2
1
1
R16
U1
U2
3
4
2
1
2
1
1
1
DESCRIPTION
50Ω resistors
5kΩ resistors
0Ω shorts (0603) (can be changed to
allow for other matching networks)
Resistor—not installed (for back-
terminating an interstage filter)
280Ω 1% resistors
Resistor—not installed (for adjusting
the RSSI output voltage range)
MAX2510EEI (28 QSOP)
10.7MHz ceramic bandpass filter
(Z
O
= 330Ω), 3-pin through-hole footprint
Murata SFE10.7MA5-A
3-pin headers (0.1" center)
Shunts
MAX2510EV-SO circuit board
MAX2510EEI data sheet
9
________________________________________________________________
Maxim Integrated Products
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX2510 Evaluation Kit
Evaluates: MAX2510
_________________________Quick Start
The following section provides instructions for operating
the EV kit as an IF transceiver. The RF ports (RXIN,
RXIN,
TXOUT, and
TXOUT)
are matched to 50Ω at
240MHz, and the second IF is configured for 10.7MHz
operation. The EV kit and the MAX2510 can be config-
ured for operation at other frequencies (see the
Detailed Description
section and the MAX2510 data
sheet).
Connections and Setup
This section provides step-by-step instructions for get-
ting the EV kit up and running in both Tx and Rx modes.
Tx Mode
Perform the following steps to set up the EV kit in Tx
mode:
1) Make the DC connections: set the power supply to
3V, and connect it to the VCC and GND terminals
on the EV kit. Set one of the voltage sources to
1.4V, and connect it to VBIAS. Set the other voltage
source to 2V, and connect it to the gain-control ter-
minal (marked GC).
2) Set the part in Tx mode by putting 3-pin jumper
TXEN in the “high” position, and jumper RXEN in the
“low” position.
3) The supply current should be near 30mA. If this is
not the case, check the voltage on the TXEN and
RXEN test points. The TXEN voltage should be at
V
CC
, and the RXEN voltage should be at ground.
4) Connect TXOUT to the spectrum analyzer using an
SMA cable. Terminate
TXOUT
with a 50Ω SMA ter-
minator.
For differential operation, TXOUT and
TXOUT
can
be combined using a balun. Connect the balun’s
output to the spectrum analyzer. Set the spectrum
analyzer to 240MHz center frequency with a 1MHz
total span.
5) Connect the local oscillator (LO) signal source to
the LO SMA connector. Set the frequency to
240MHz and the amplitude to -13dBm. You will see
a small amount of LO signal present at the center of
the spectrum-analyzer display.
6) Set both channels of the baseband-signal genera-
tor to deliver sine waves at 500mVp-p at a fre-
quency of 100kHz. To achieve maximum sideband
suppression, be sure that there is a precise 90°
phase difference between these two sinusoidal
signals. Connect the first signal to the I input. You
will see a double sideband signal (DSB) on the
spectrum analyzer at 240MHz, with the lower side-
band at (240MHz - 100kHz) and the upper side-
band at (240MHz + 100kHz). Connect the other
signal to the Q input. If the phase difference is set
correctly, you will see a cancellation of the side-
bands. Which sideband is canceled depends on
which input leads the other in phase. Swapping
the I and Q connections at the board’s input sup-
presses one or the other sideband. Leave the part
set to transmit the upper sideband (USB) when fin-
ished. The rest of these instructions assume the
Test Equipment Required
This section lists the test equipment recommended for
verifying operation of the MAX2510. It is intended only
as a guide; some substitutions may be possible.
• Two RF-signal generators capable of delivering at
least 0dBm of output power up to 500MHz
(HP8656B, HP8648A, or equivalent). One generator
is required for the local oscillator (LO) source in
both transmit (Tx) and receive (Rx) modes. The
other is required for the Rx input signal in Rx mode.
• An RF spectrum analyzer that can cover the trans-
mitter’s output frequency range, as well as a few
harmonics (HP8560E, for example).
• A baseband-signal generator that can produce two
outputs in quadrature (sine and cosine waves) at
levels of approximately 500mVp-p. This is neces-
sary to evaluate the transmitter’s sideband suppres-
sion. The HP8904A/Opt. 002 generator provides
sine and cosine outputs at frequencies up to
600kHz.
•
Optional:
An RF 180° hybrid combiner or balun
(Anzac H-9 or equivalent). This is used for differen-
tial coupling into the RXIN,
RXIN
connections on the
receiver or the TXOUT,
TXOUT
connections on the
transmitter. If a balun is not available, these inputs
and outputs can be evaluated in a single-ended
configuration, at a slight performance cost.
• A voltmeter for measuring the RSSI output voltage.
• An oscilloscope for observing the limiter output
signals.
• A power supply that can provide up to 50mA at
+2.7V to +5.5V.
• Two 0V to 5V adjustable voltage sources for provid-
ing gain-control (GC) pin voltage and the VBIAS
voltage for the I and Q inputs.
• Two 50Ω SMA terminators
• Several 50Ω SMA cables
2
_______________________________________________________________________________________
MAX2510 Evaluation Kit
transmitter is set in USB mode and the lower side-
band (LSB) is the suppressed sideband. If the
application requires LSB, reverse the relevant
instructions. The EV kit also accommodates differ-
ential I and Q inputs. (Refer to the
Detailed
Description
section.)
7) The USB output power should be approximately
0dBm with GC = 2V. Test the GC function by slowly
lowering the voltage on the GC pin from 2V to 0V.
You will see at least a 40dB change in USB power
over this voltage range.
8) When the transmitter is working properly, you may
wish to test other features, such as shutdown mode
(both TXEN and RXEN jumpers set to “low”. The I
and Q inputs can be adjusted to check transmitter
gain over frequency, VBIAS voltage, etc.
Rx Mode
This section describes how to connect and use the
MAX2510’s receiver section.
1) Remove the I and Q input signal sources to prevent
crosstalk into the receiver during Rx-mode mea-
surements. The GC and VBIAS voltage supplies
have no function in Rx mode.
2) Switch the part into Rx mode by moving the RXEN
jumper to the “high” position and the TXEN jumper
to the “low” position.
3) Change the LO frequency to equal the desired Rx
frequency minus 10.7MHz. This provides a
10.7MHz downconverted signal into the off-chip fil-
ter (a 10.7MHz bandpass type). For a 240MHz Rx
frequency, the LO frequency should be (240 - 10.7
= 229.3 MHz). Leave the LO power level at -13dBm.
4) Connect RXIN to a second RF-signal generator
using an SMA cable. Terminate
RXIN
with 50Ω.
For differential operation, connect the signal gener-
ator to RXIN and
RXIN
through a balun. Set this
generator’s frequency to 240MHz at -30dBm of out-
put power.
5) Connect an oscilloscope to the limiter outputs
LIMOUT and
LIMOUT.
A 2-channel oscilloscope
with low-capacitance probes is ideal. The signals
from LIMOUT and
LIMOUT
should be approximate-
ly 600mVp-p and out-of-phase with each other.
6) Connect a voltmeter to the RSSI test pad in the
upper-left corner of the EV kit to monitor the RSSI
output voltage. For -30dBm of RXIN power, the
RSSI voltage should be 1.8V. Lower the input power
in 10dBm steps, observing the decrease in RSSI
output voltage of about 20mV per 1dB change in
input power. Return the power level to -30dBm.
7) Observe that the signals at LIMOUT and
LIMOUT
remain at constant level over the RXIN power range.
Advanced System
Power-Management Features
Besides the Tx and Rx modes previously mentioned, the
MAX2510 supports two other operating modes: shutdown
and standby. Bring both TXEN and RXEN jumpers to the
“low” position, putting the part in shutdown mode and
reducing the supply current to 2.0µA (typical).
To enter standby mode, bring both TXEN and RXEN
jumpers to the “high” position. This reduces the supply
current to about 0.5µA while leaving the VREF generator
active (for fast switching into receive mode).
Evaluates: MAX2510
_______________Detailed Description
The following section covers the EV kit’s circuit design
in detail. (See the MAX2510 data sheet for additional
information.)
Baseband Inputs
The I,
I,
Q, and
Q
pins comprise the quadrature modu-
lator’s baseband inputs. They require external DC bias-
ing to set a common-mode level of approximately 1.4V.
On the EV kit, this voltage is provided by external resis-
tors and a voltage supply (VBIAS). The I and Q pins are
AC coupled to SMA connectors, which induces a high-
pass cutoff of approximately 300Hz. The
I
and
Q
pins
are biased to the common-mode voltage and AC
grounded. Test points on the EV kit allow flexible
access to these pins if the application requires differen-
tial drive.
Transmitter Output
The MAX2510’s Tx outputs (TXOUT and
TXOUT)
are
high-impedance open collectors; therefore, external
inductors are used for proper biasing. DC-blocking
capacitors are used to connect to these outputs. The
inductors and capacitors act only to provide biasing;
they do not set the output impedance. For single-ended
applications, terminate
TXOUT
with a 50Ω terminator.
Alternatively, replace L4 with a 0Ω short. Refer to the
MAX2510 data sheet for more information on matching
this port.
Receiver Input
The Rx inputs (RXIN and
RXIN)
require an impedance-
matching network for optimum performance. The Rx
inputs are matched to 240MHz on the EV kit as
shipped. The input matching network comprises a
series capacitor from each Rx input SMA connector to
the part, as well as a shunt inductor across RXIN and
RXIN.
The EV kit layout provides space for additional
components: one series element on each side and a
3
_______________________________________________________________________________________
MAX2510 Evaluation Kit
Evaluates: MAX2510
shunt element across the inputs. The additional series
elements have been replaced by 0Ω shorts, and the
additional shunt element is not installed. Refer to the
MAX2510 data sheet for more information on designing
a matching network for this port.
______________________Layout Issues
A good PC board is an essential part of an RF circuit
design. The EV kit PC board can serve as a guide for
laying out a board using the MAX2510.
Receiver Output
The receive downconverter mixer’s output appears at
the MIXOUT pin (a current source that can drive a
165Ω load to 2Vp-p). The MIXOUT pin is terminated
with a net 330Ω (R10 + R11) for proper match to the
bandpass filter (Z
O
= 330Ω). Therefore, the net load at
MIXOUT is 330Ω
330Ω = 165Ω.
The EV kit design allows separate testing of the
MAX2510’s Rx mixer and limiter sections for testing the
Rx mixer only. Coupling capacitor C20 is used to con-
nect the node between R10 and R11 to an external
SMA connector (MIXOUT). For these tests, the filter
(U2) must be removed, and R10 replaced with a 140Ω
resistor. This network has some attenuation, but pre-
sents the correct impedance to the MIXOUT pin and
provides a nearly 50Ω output impedance for measure-
ment. The attenuation is 11.2dB.
Rx Inputs and Tx Outputs
The layout of the RXIN and
RXIN
input matching net-
work should be layed out symmetrically to provide the
best input balance if used as a differential input. The
TXOUT and
TXOUT
biasing networks should also be
layed out symmetrically to present an equal load
impedance on each pin.
Baseband Inputs
The MAX2510’s I,
I,
Q, and
Q
inputs are high imped-
ance; take care to minimize potential unwanted cou-
pling into these pins. The easiest way to accomplish
this is to keep the trace length to a minimum.
Power-Supply Decoupling
Each V
CC
node on a PC board should have its own
0.047µF decoupling capacitor. This minimizes supply
coupling from one section of the MAX2510 to another.
A star topology for the supply layout, in which each
V
CC
node on the MAX2510 circuit has a separate con-
nection to a central V
CC
node, can further minimize
coupling between sections of the MAX2510.
Limiter Input
The MAX2510 EV kit can be modified to allow separate
testing of the limiter only, similar to the receive mixer in
the previous section. The filter (U2) must be removed.
This allows the limiter SMA connector to be used as a
direct input to the limiter.
Limiter Output
The downconverted, limited signal appears at the
LIMOUT and
LIMOUT
pins as a 1.2Vp-p differential
voltage (600mVp-p per side). For single-ended use, the
unused side can be left open. The limiter outputs can
deliver this voltage across a load as low as 250Ω.
4
_______________________________________________________________________________________
MURATA FILTER
SFE10.7MA5-A
3
R15
280Ω
2
MIXOUT
SMA
GND
C17
50Ω
R11
50Ω
C20
0.022µF
R10
280Ω
C2
10µF
C23
0.1µF
U2
1
V
CC
V
CC
LIMIN
SMA
C29
0.022µF
C21
0.1µF
26
1
LIMIN
RXIN
R1, 0Ω
25
RXIN
SMA
MIXOUT
27
C25
10pF
GND
VREF
GND
28
20
Figure 1. MAX2510 EV Kit Schematic
2
CZ
C1
0.01µF
TP1
U1
3
CZ
4
RSSI
GC
L3, 47nH
V
CC
8
C30, 20pF
V
CC
GND
TXOUT
6
LO
LO
I
Q
I
10
GND
LIMOUT LIMOUT TXEN
13
14
11
12
19
RXEN VA
V
CC
C14
0.001µF
V
CC
HIGH
HIGH
V
CC
1
2
LOW
LOW
3
JU9
RXEN
VIL
21
V
CC
Q
Q
15
18
16
17
I
C12
0.1µF
C7
0.1µF
I
Q
9
23
C5
OPEN
R9
OPEN
C31, 20pF
TXOUT
24
RXIN
5
TP2
MAX2510
22
RXIN
SMA
R5, 0Ω
L2
82nH C18
10pF
RSSI
R16
OPEN
C2
300pF
TXOUT
SMA
V
CC
C22
0.1µF
GC
C4
0.047µF
7
C6
47pF
47pF
C8
C3
0.01µF
LO
SMA
R3
50Ω
L4, 47nH
C10
OPEN
C19
0.001µF
TXOUT
SMA
C9
0.1µF
I
SMA
C13
0.1µF
Q
SMA
LIMOUT
SMA
R13
0Ω
R2
0Ω
R6
0Ω
1
JU8
2
TXEN
3
R12
0Ω
C15
0.001µF
R4
5kΩ
R8
5kΩ
R14
5kΩ
R7
5kΩ
VBIAS
C27
0.1µF
Evaluates: MAX2510
_______________________________________________________________________________________
LIMOUT
SMA
MAX2510 Evaluation Kit
5
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